(1) Field of the Invention
This invention relates generally to apparatus for fitting eyeglass frames to an individual. More particularly, the present invention relates to an eyeglass frame fitting system that can be operated by any individual without the need for any special training or knowledge.
(2) Description of Related Art
In the typical case, when a person has diminished or impaired vision, such a person must have a highly-skilled optometrist or optician select corrective lenses along with eyeglass frames that are tailored to fit the particular individual's unique physical characteristics such as head shape and size. To accomplish this task, the optometrist or optician must either employ sophisticated mechanical devices, e.g., pupilometers (for example the Corneal Reflection Pupilometer by Essilor Technologies of America, Oldsmar, Fla.) and millimeter rulers (for example the PD (pupil distance) millimeter ruler by Marchon, Melville, N.Y.), that are used to take a variety of measurements needed to fashion eyeglass frames. Alternatively, the optometrist or optician must place an eyeglass frame of the exact size (eye size, bridge width and temple length) on the individual to determine fit.
Measurements that must be taken to fashion a properly fitting pair or eyeglass frames include horizontal pupil distance, vertical pupil height, nose width, temple length and head width. These measurements are taken to determine the optical center location of prescription eyeglass lenses that are incorporated into the eyeglass frames. In order to operate any of the known measuring devices properly, the device operator must first receive comprehensive training. Because sophisticated equipment and trained professionals have to be employed to take the necessary measurements, additional expense is unavoidably incurred.
Another problem associated with the use of sophisticated measuring devices, currently used in the field of optometry, which require skilled optometrists or opticians to operate the devices, concerns the potential for error in the measurements taken. The problem is inherent in the procedures used to take the measurements. For example, to take the horizontal and vertical pupil measurements, some of the older devices that are still in use require the trained operator to look through the device at the individual while making adjustments to the measuring device. With one such device, the operator aligns cross hairs in the measuring device with the individual's pupil. By following this procedure, the operator's eye is used to make the alignment. In doing so, the added element of the operator can lead to errors such as parallax. Any movement by the individual in relation to the measuring device, however slight and virtually imperceptible to the individual, when measurements are taken, could lead to measurement errors.
Similar problems arise with the use of millimeter rulers. For example, the PD (pupil distance) millimeter ruler (Marchon, Melville, N.Y.), requires an optician or trained technician to manipulate the ruler to take measurements. To operate the ruler, the optician or technician must align the ruler relative to the individual's head. Proper ruler alignment is crucial to obtain accurate measurements. Any error in ruler alignment by the optician or technician translates into inaccurate measurements and improper fitting eyeglass frames.
Following the measuring devices employing cross-hairs, the next generation of measuring devices, pupilometers, employ beams of light to take measurements of inter-pupil distance and to place the optical center in eyeglass frames. For example, a Corneal Reflection Pupilometer (Essilor Technologies of America, Oldsmar, Fla.) requires a technician to initially place the device on an individual's face over the individual's nose so that the individual looks through one side of the pupilometer. The centerline of the pupilometer must be aligned with the saggital plane of the individual's head in order to obtain accurate measurements.
The pupilometer contains lights which shine beams of light over the individual's pupils. The technician must manipulate the pupilometer to align the beams of light over the individual's pupils. When the light beams are centered over the pupils, readings are taken by the technician from calibrations on the pupilometer.
Due to the incorporation of light beam technology, pupilometers eliminate parallax problems. However, pupilometers are expensive and require the assistance of an optician or technician trained to use pupilometers.
Accordingly, there is a need for a cost effective eyeglass frame measuring device that can be operated by an individual in need of corrective lenses without any special training and without the measurement problems associated with the use of the sophisticated measuring devices currently in use.